The Magpies’ record all-time goalscorer ripped into the United squad for their “shambolic defensive display” during the sorry 3-1 defeat at Southampton on Saturday.
Shearer singled out the fact that Steven Taylor and Fabricio Coloccini are still Newcastle’s centre-backs seven years after the pair were relegated with United to highlight the Magpies’ failed recruitment strategy.
The ex-England captain also accused Georginio Wijnaldum and Moussa Sissoko of going “missing again away from home”.
Writing in his column for The Sun, Shearer seethed: “If Newcastle are going down, they could at least go down with a fight.
“At Southampton on Saturday they showed no fight at all until it was obvious they could not win.
“They were hopeless for the first 45 minutes and by the time they did improve slightly in the second half, it was already too late.”
Shearer was across at Augusta taking in The Masters but watched the Newcastle game on TV with Sir Alex Ferguson.
A couple of people commented that Newcastle had talented players, to which Shearer wrote: “Have they? At the moment it is hard to name them.
“Because all I saw on Saturday was Georginio Wijnaldum and Moussa Sissoko go missing again away from home, Aleksandar Mitrovic barely touch the ball and another shambolic defensive display.
“Recruitment has been a big problem at the club. Nobody can dispute that. It is the biggest reason for Newcastle’s decline since they finished fifth in the Premier League in 2012.
“But those that have been brought in at Newcastle have either not been good enough for Premier League football or not been up for the challenge.
“It is all well and good having ability but ability alone in a relegation scrap is not enough. You need characters that are going to fight.
“You need players that are going to roll up their sleeves and have a right good go.
That has not been the case for Newcastle unfortunately.”